Various thermostatic valves, in particular for the coolant circuit of a motor vehicle, have been disclosed in the prior art. DD 96 766, which is incorporated by reference herein, and DE 1917 925, which is incorporated by reference herein, each disclose a thermostatic valve with an actuator having an expansion material filling, in which an actuating piston is accommodated in a housing filled with the expansion material and protrudes out of the housing with a piston rod or a plunger, wherein the end side of the piston rod or plunger is mounted in the housing of the thermostat. When the expansion material expands, the housing of the actuator is shifted relative to the piston or to the piston rod/plunger and, in the process, slides in turn at its end opposite the support of the piston rod/plunger in an opening of the housing of the thermostat counter to the restoring force of a spring. A plate is connected to the housing of the actuator as the switching element, said plate rising from an abutment when the expansion material expands and opening up a passage opening between fluid inlet and fluid outlet.
The actuator here is fixedly clamped at its one distal end by means of the piston rod/plunger and, at its opposite distal end, is mounted in a sliding manner on the housing of the actuator.
This arrangement of the bearings may lead to tilting of the actuator, if the sealing connection and guidance of the piston rod into the housing of the actuator are not optimally formed, thus resulting in kinematics which are not reproducible.